The present invention relates to apparatus for transporting strips, webs, bands, tapes or like flexible materials, especially for transporting photosensitive materials in and from a copying machine, such as a roll copier. More particularly, the invention relates to improvements in apparatus which can be utilized to transport freshly exposed photosensitive material from a copying machine into a cassette or an analogous receptacle, especially into a cassette which is equipped with means for automatically attaching the leader of photosensitive material to a rotary component in the form of a core whereon the material is convoluted and stored for transport to other processing stations.
It is already known to equip cassettes for exposed photographic paper or like photosensitive material (hereinafter called web for short) with a so-called catcher mechanism which is movable under or against the action of one or more springs in order to assume an operative position and to thus steer the leader of the web into the range of the rotating core. A copying machine which cooperates with such cassettes is normally equipped with means for terminating the activation of the catcher mechanism when the leader of the web is attached to the core; this is desirable and advantageous in order to ensure that the component parts of the catcher mechanism cannot interfere with accumulation of a requisite supply of convoluted web on the core. As a rule, the copying machine comprises a mechanism which advances the leader of the web toward and through an opening in the housing of the copying machine and thereupon into the interior of the cassette which comprises a catcher mechanism, normally a mechanism of the type having several mobile members in the form of arms which are pivotable or otherwise movable between operative and inoperative positions. When they assume the operative positions, such arms ensure that the leader of the web is guided toward and into contact with the rotating core. The arms have suitably configurated portions which surround the core during threading of the leader into the interior of the cassette, and such movements of the arms can be effected in automatic response to proper positioning of the cassette with reference to the copying machine and/or vice versa. As soon as the first convolution or convolutions of the web properly adhere to the core, i.e., as soon as the core is capable of drawing the web into the interior of the cassette, the arms of the catcher mechanism should be retracted to allow for unimpeded accumulation of successive convolutions of the web on the core.
Catcher mechanisms of the just outlined type are disclosed, for example, in U.S. Pat. No. 3,395,870, German Pat. No. 1,187,914 and German Offenlegungsschrift No. 26 17 233. The Offenlegungsschrift discloses a catcher mechanism cooperating with a projection which is fixedly mounted on the copying machine and serves to activate (i.e., move to operative position) the catcher mechanism in an empty cassette which is about to receive a web of exposed photosensitive material. The projection must move the mobile parts of the catcher mechanism against the opposition of one or more springs which are installed in the casing of the cassette. The just discussed apparatus further comprises a discrete disengaging mechanism which must be activated as soon as the attachment of the leader of the web to the core of the cassette is completed in order to return the component parts of the catcher mechanism to their inoperative positions. The disengaging mechanism must be capable of performing such function in spite of the fact that the projection is rigidly connected to the copying machine, i.e., that the position of the projection cannot be changed on completion of the threading and attaching operations. To this end, the customary roll which is installed in the web-admitting opening in the casing of the cassette is coated with a friction lining which can entrain by friction a lever serving to trigger the operation of a linkage which, in turn, moves the component parts of the catcher mechanism to their inoperative positions. The lining can frictionally engage and pivot the aforementioned lever when the attachment of the leader of a web to the core in the casing of the cassette is completed. This is due to the fact that the web is supposed to be tensioned in response to proper attachment of its leader to the core of the cassette, and such tensioning of the web results in frictional engagement with the roll whose lining then pivots the lever with the result that the linkage initiates the movement of component parts of the catcher mechanism to their inoperative positions.
A drawback of the just discussed apparatus is that it is very prone to malfunction and is often likely to deactivate the catcher mechanism prior to completion of attachment of the leader of the web to the core in the interior of the cassette. If the extent of frictional engagement between the lever and the roll, at which the lever triggers the operation of the aforementioned linkage, is too low, deactivation of the catcher mechanism will be premature. On the other hand, if the selected friction is excessive, the catcher mechanism is likely to remain in operative position for an excessive interval of time and to thus interfere with winding of the web onto the core. Moreover, the mechanism which is disclosed in the German Offenlegungsschrift is quite complex and occupies a substantial amount of space.